Estrogen and androgen appear to influence brain function in females at puberty. Environmental and cultural factors interact with the biological effects of estrogen and androgen on he brain an consequently on cognition and behavior. Women with Turner syndrome have dysgenetic ovaries that do not produce estrogen or androgen, before or at puberty. Therefore, Turner syndrome represents a unique, sex hormone-deficient, model in which to study the biological effects of androgen on cognition and behavior. The overall goal of this project is to study design. we will study (1) two Turner syndrome groups: (A) androgen and (B) no androgen and (2) an age-matched, normal female control group. The specific aims of this project are to: 1) examine the effects of androgen on cognitive and social function in adolescent (11-13 years), growth hormone-treated girls with Turner syndrome, and 2) documented the differences and similarities in cognitive and behavioral function between adolescent Turner syndrome girls (treated or not treated wit androgen) and age-and VIQ-girls treated with androgen, or not androgen-treated: (1) Turner syndrome girls treated with androgen versus no androgen will perform better on the tests of visual-spatial ability and visual-motor ability, (2) Turner syndrome girls treated with androgen versus no androgen will not perform differently on tests of attention, executive function, social function, and affective competence, (3) Turner girls treated with androgen for 2 years will demonstrate the greatest treatment effects, compared to girls treated for 1 year, and (4) androgen treatment will significantly reduce the differences between Turner syndrome and normal controls girls on tests executive function, social function, and affective competence. This investigation of adolescent cognitive and social development is an important step in understanding normal brain development. In addition, these data will determine how to optimize cognitive function in Turner syndrome, and will extend knowledge of the underlying mechanisms of sexual dimorphism.